Now that summer has finally arrived in Frankfurt, here are some ideas of things to do on a sunny day:
1. Visit the zoo. The U-Bahn lines U6 and U7, tram line 14 and bus nr. 31 all stop there.
2. Take a ride on an open-top bus around the city centre.
3. Visit the Palm Garden and see the tropical and sub-tropical plants or take a ride on the Palmen-Express.